Abnormal EEGs In The Sleep Lab

Patti Baumgartner,R. EEG/EP., CNIM

Danny Glover Sir Isaac Newton Pope Pius IX Socrates Napoleon Charles Dickens maybe someone you know?

What do these people have in common?

They all have epilepsy.

Answer

It is estimated that at least 2/3 of seizures occur in sleep.

Not everyone who has a seizure has epilepsy

Some seizures can hardly be noticed, while others are totally disabling.

What percentage of seizures occur in sleep?

A seizure is a sudden surge of electrical activity in the brain that usually affects how a person feels or acts for a short time.

Seizures are not a disease in themselves. Instead, they are a symptom of many different disorders of the brain.

Not everyone who has a seizure has epilepsy.

What is a seizure?

Epilepsy is a medical condition that produces seizures affecting a variety of mental and physical functions.

When a person has 2 or more unprovoked seizures they are considered to have epilepsy.

Definition of Epilepsy

Any one of us can have a seizure if the conditions are right.

Drugs Hypoglycemia High fever ECT Infectious disease Meningitis/encephalitis

Etiology of Epilepsy

Quick Anatomy Lesson

4 lobes of the brain

Plan for the futureSolve complex problems Express and control emotional behaviorCoordinate complex skilled movementsSome aspects of speech

Frontal Lobe

In most people the temporal lobes have somewhat different functions The left temporal lobe generally helps us to understand language, and speak.The right temporal lobe helps us to remember things.

Temporal Lobe

Includes sensory areas, responsible for feelings of temperature, touch, pressure and pain.

Parietal Lobe

Primary function is vision

Occipital

Seizures are classified into 2 categories or groups:

Partial and Generalized

Classification of Epilepsy

Involve only a portion of the brain at the ONSET.

They are further divided into two parts: Simple partial, in which consciousness is not

impaired Complex partial in which consciousness is

impaired.

Partial Seizures

These seizures are commonly called grand mal. And by definition begin with loss of consciousness.

Typically each seizure has 2 phases, tonic and clonic.

Tonic Phase consists of an increase in muscle tone which causes stiffening.

Clonic Phase consists of alternating tightening and relaxing of muscles--Jerking

Generalized seizures

Another type of generalized seizure is the Atonic Seizure.

The seizure consists of loss of all strength rather than becoming stiff. They last only a few seconds so it is impossible to accurately determine the patient’s level of consciousness.

Generalized seizures

Brief episodes of staring. May have some associated eye blinking/fluttering, or lip smacking.

Spells last only a few seconds Start in Childhood, disappear by late teens

Absence Seizures

Seizures that begin with an abnormal electrical

discharge from a limited area of the brain are called partial seizures.

Two kinds:Simple complexPartial Complex

Partial Seizures

The specific area of he brain where each of these seizures begins determines what the seizure looks like.

Commonality is that the person having the seizure remains alert and can remember what happened.

Sometimes called focal seizures

Simple Partial Seizures

These seizures begin in a small area of the temporal or frontal lobe, but they quickly involve areas that affect alertness and awareness

Consciousness is lost, the patient has no memory of the event

Complex Partial Seizures

Both simple and complex partial seizures can spread , resulting in secondarily generalized tonic clonic seizures.

In the EEG world this is called secondary subcortical synchrony

Secondary generalized seizures

Rebecca Clark-Bash 23

Summary of Clinical & EEG Features of Epileptic SeizuresSeizure Usual

DurationLoss of Consc.

Post-IctalConfusion

ICTALEEG

SimplePartial

5-10 sec NO NO Focal Spikes (NL)

Complex Partial

Variable5-10 sec1-2 min

YES YES Focal orLat. Spike

Absence 5-10 /secClustering

YES NO Gen.3 /sec S & W

Gen.Tonic-Clonic

1-2 min YES YES Gen. HighAmp Spikes

Tegretol Carbatrol ZarontinFelbatrol Gabitril KeppraLamictal Lyrica DilantinTopamax Trileptal DepakeneDepakote

Medications for Epilepsy

Rebecca Clark-Bash25

Term Definition Ictal EEG

Describes the recording during the event

Interictal EEG Describes the recording in between

each event Postictal EEG

Describes the period of time immediately following an event

Any paroxysmal rhythmic frequency (e.g. beta, alpha, or even delta) may also be classified as epileptiform.

Certainly the most common types of Epileptiform activity are: spikes, sharp waves, spike and waves

What is Epileptiform Activity

A wave with a duration of 80 msc or less, usually negative, standing out from the background.

Definition of a Spike

A wave with a duration of 120-80 msc, usually negative, standing out

from the background.

Definition of a Sharp wave

How to measure a spike/sharp wave30 second epoch

Spike followed by a slow wave

Spike and Wave

31

What do you see on the EEG

The signature of epilepsy:

“cat”

Example #1 Sleep parameters

Example #1 EEG Parameters

Eye Blink artifact

Answer

Example #2 Sleep Parameters

Sample #2 EEG Parameters

Asymmetrical Alpha. Alpha activity is higher amplitude on the

Sample #2 Answer

Example # 3 Sleep Parameters

Example #3 EEG Parameters

Generalized spike and wave

Sample #3

Example #4 Sleep Parameters

Example #4 EEG Parameters

Multifocal Spikes

Sample #4

Sample #5 Sleep Parameters

Sample #5 EEG Parameters

C4 spikes

Sample #5

Sample #6 Sleep Parameters

Sample #6 EEG

Generalized Spike and Wave

Sample #6

Sample #7 Sleep Parameters

Sample #7 EEG Parameters

Generalized Polyspike and Wave

Samle #7

Sample #8 Sleep Parameters

Sample #8 EEG Parameters

Focal slow F7 T3

Sample #8

Sample #9 EEG Parameters

Sample #9 Sleep Parameters

Focal Slow, best seen on slow paper speed

Sample #9

Bernard M. Abrams, M. D. Susan Gersh, R. EEG T. Rebecca Clark Bash, R. EEG/EP T., CNIM,

F.ASNM Terry O’Brien

Many Thanks to Those That Helped

1. Eye Blink 2. Asymmetrical Alpha 3. Generalized Spike and Wave 4. Multifocal Spikes 5. C4 focal Spike 6. Generalized spike and wave 7. Generalized Polyspike and wave 8. Focal spikes F7 and T3 9. Focal slowing T3 best seen on Sleep

Parameters (slow speed)

Answers to Sample Wave Forms